Gov. Jon Corzine is expected to be endorsed by New Jersey’s major police and fire unions. The endorsement blitz is to begin today with announcements from the Port Authority Police Benevolent Association and the Firemen’s Mutual Benevolent Association. Endorsements from the Fraternal Order of Police and Professional Firefighters Association of New Jersey are planned for Sunday. The state Police Benevolent Association is expected to make an endorsement in the race at its convention next month. Union officials cited Corzine’s commitment to funding public safety and maintaining safe staff levels, even during the recession. Republican gubernatorial candidate Chris Christie has riled unions during the campaign with his pledges to reduce the union work force and reform the pension system if elected. APP